A secagem no processamento da castanha-do-Brasil como ferramenta de prevenção da contaminação por aflatoxinas

Abstract

The Castanheira (Bertholletia excelsa H.B.K), native to the Amazon, grows in regions with hot and humid climates. Its almond known as Brazil nut is nutritionally rich, as it is composed of fatty acids, proteins of high biological value, fibers, minerals and selenium. Aflatoxin is a mycotoxin produced by the fungi Aspergillus flavus and Aspergillus parasiticius, which can contaminate unprocessed or improperly processed nuts (such as Brazil nuts). These fungi produce metabolites toxic to human and animal health, with emphasis on the types: B1, B2, G1 and G2. The drying process is the main stage in the nut production chain, as this procedure can help prevent the development of mycotoxins and thus provide a quality product. Therefore, water activity levels below 0.7 must be maintained, since from this point on, the growth of pathogenic microorganisms starts. From these aspects, the objective of this work was to analyze the water contents (water and moisture activity) present in chestnuts from a processing plant as a way of validating the drying process carried out by it in the 2019 and 2020 harvests, quantifying also aflatoxins in high performance liquid chromatography (HPLC) equipment for comparative effect. The results obtained showed the water contents of the two harvests, as well as the processed and unprocessed samples. It was observed that the processed samples had lower levels of humidity in relation to the unprocessed samples, something seen in the two harvests. However, no significant differences were observed between one crop and another regarding moisture content. It was also observed that there was no positive sample for AFL at aw <0.9. It is plausible to note that the drying process with time and temperature control as well as the storage conditions after the process carried out at the beneficiation plant had a direct impact on the final quality of the product. It is important to highlight that the procedure must be used not only after the beginning of the industrial process, but also from the moment of raw material collection.